Material and energy demand in actual and suggested maintenance of sugarcane harvesters

Abstract

Since green revolution agriculture has provided more yield vis-a-vis more energy demand. Currently, in the search for bioenergy, Brazilian sugarcane has gained attention, but as an energy source its efficiency has to be monitored. Energy balance is the physical evaluation of required inputs, but rarely studies present data about material. For agricultural machinery, the specific determination of the energy demand is required, since indices from automobile industry from late 1960s are still adopted. Besides, maintenance is usually based on a percentage of the energy spent on manufacturing. This study evaluates material and energy demand in the maintenance of sugarcane harvesters as: a) suggested by the manufacturer and b) actually done by sugar mills. So, part replacements, labour and material requirements are surveyed. Energy flows are determined by the material demand and material's energy embodiment. According to manufacturer, the maintenance requires 72.8% (2.52 TJ) of the total energy in the life cycle of a sugarcane harvester, while the actual maintenance represents 95.0% (17.93 TJ) of the total energy. The indices change from 158.9 MJ h−1 to 869.7 MJ h−1 (regarding life time); from 203.2 to 1,112.0 MJ kg−1 (regarding mass) and from 13.26 to 72.59 MJ kW−1 (regarding power).